go--function-name: return nil for anonymous functions
go--function-name: return nil for anonymous functions

Also add a similar API to the other functions that modify things that
don't apply to anonymous functions; an optional argument that toggles
if the function should ignore anonymous functions or not. The function
returns nil if the argument is nil and point is in an anonymous
function.

dominikh/go-mode.el,emacsmirror/go-mode